Using the Legend to Control the Layers
The legend is a graphical representation of all the map layers in the current project. The position of the legend is the left hand side of the screen. The legend offers layer manipulation functionality including but not limited to changing a layers symbology or the order of display for the layers. The legend is always displayed
- Visibility Checkbox: This indicates whether a layer is always visible (checked) on the map screen, or always hidden (blank).
- Text: This is the name of the layer.
Each line represents a layer of data that's in the main view. The image to the right of the legend is an indicator to help identify the data layer. If, for example, the user had a polygon Shapefile that was filled, the colour in this image would be the same as the fill colour. For a line Shapefile, the colour here will match the colour the line is drawn with.
Right Click Functionality
If users right click (right mouse button) over the Legend, the menu below shows;
[ADD GROUP] bunch a selected set of layers under a common header
[REMOVE LAYER] ??? Removes a layer from the project
[CLEAR LAYERS] - Removes all layers
[ZOOM TO LAYER] - Zooms the map to the full extent of the selected layer
[VIEW ATTRIBUTE TABLE] ??? this is the table behind most layers which can contain a range of information on shapes, such as names, size, x & y coordinates etc.
Changing the Drawing Order:
The legend indicates the order that layers are drawn in. The first layer in the legend is the top layer of the map. The last layer in the legend is the bottom layer on the map. The layers are drawn from bottom up, hence the bottom layer is drawn first then the last but one layer and so on. As a result is it important to carefully order the users map layers so data is not obscured by layers placed on top.
If you have imagery displayed, this is best ordered to the bottom of the layer list, to make it background for all other layers on top.
To change the order of a layer, in the legend, click and drag a layer to the desired location.
Using Groups to Order Layers
If you have large numbers of layers loaded, the legend can become cluttered and require users to scroll up and down to find the relevant layers. The Group option allows you to bunch layers together, and expand or collapse this group or re-order a whole group of layers.
To add a new Group;
- Right-click on the Legend and select [ADD GROUP]
- Name the Group in the dialog and confirm
To add layers into a Group;
- Select the appropriate Group you want to add layers to
- Add the layers as per normal, or
- click and drag existing layers into the group from other sections of the legend